When you choose to do something in public that gets noticed, it’s hard to stay out of the public eye. And the more outrageous and subversive whatever it is you do is, the more people want to unmask you. This has been the case with the British graffiti artist who goes by the pseudonym of Banksy and whose identity has, sadly, recently been unmasked ... not by investigative reporting or being outed by aanyone close to him but by technology.

Before I explain how Banksy was revealed to be a man named Robin Gunningham, perhaps I should briefly explain Banksy’s history. Banksy’s work is described by Wikipedia as:

… satirical street art and subversive epigrams [that] combine dark humour with graffiti executed in a distinctive stenciling technique. His works of political and social commentary have been featured on streets, walls, and bridges of cities throughout the world.

His art, which really is remarkable, has attracted enormous critical and public attention since it started appearing in the early ‘90s and even small works by Banksy have been sold for hundreds of thousands of dollars. But despite all of the interest and investigation into Banksy’s identity, there was, until technology got involved, only circumstantial evidence publicized in 2008 by the UK’s Daily Mail tabloid that Banksy was, in fact, Gunningham.

The technology in question is something called “geographic profiling” which was developed for criminal investigations. This methodology:

… analyzes the locations of a connected series of crimes to determine the most probable area of offender residence. By incorporating both qualitative and quantitative methods, it assists in understanding spatial behaviour of an offender and focusing the investigation to a smaller area of the community. Typically used in cases of serial murder or rape (but also arson, bombing, robbery, terrorism and other crimes), the technique helps police detectives prioritize information in large-scale major crime investigations that often involve hundreds or thousands of suspects and tips.

The technique is also applied in disciplines such as biology where it is used for analyzing the spread of infectious diseases. In this case, in a study published in the Journal of Spatial Science, researchers at Queen Mary University of London analyzed where Banksy’s artworks had appeared, and correlated them with respect to one another and “anchor points” which were the homes of people suspected of being Banksy. The study’s abstract explains:

The pseudonymous artist Banksy is one of the UK’s most successful contemporary artists, but his identity remains a mystery. Here, we use a Dirichlet process mixture (DPM) model of geographic profiling, a mathematical technique developed in criminology and finding increasing application within ecology and epidemiology, to analyse the spatial patterns of Banksy artworks in Bristol and London. The model takes as input the locations of these artworks, and calculates the probability of ‘offender’ residence across the study area. Our analysis highlights areas associated with one prominent candidate (e.g., his home), supporting his identification as Banksy. More broadly, these results support previous suggestions that analysis of minor terrorism-related acts (e.g., graffiti) could be used to help locate terrorist bases before more serious incidents occur, and provides a fascinating example of the application of the model to a complex, real-world problem.

According to a BBC article, one of the researchers, Steve Le Comber, commented:

"What I thought I would do is pull out the 10 most likely suspects, evaluate all of them and not name any… But it rapidly became apparent that there is only one serious suspect, and everyone knows who it is. … I’d be surprised if it's not [Gunningham], even without our analysis, but it's interesting that the analysis offers additional support for it.”

This demonstration of what is a powerful technology with wide applicability not only in law enforcement was a clever and impressive experiment but it’s sad that Banksy has now been unmasked. As a sort of artistic Scarlet PimpernelBanksy's career has been fascinating and delightfully mysterious; exposing him just makes the world a little less exciting.